Ladder of working vehicle

Abstract

A ladder in a multi-step structure includes: first front and rear connecting members that are connected to a vehicle body and between a wheel and an end of the vehicle body and that are juxtaposed with a predetermined space; a first step board that is connected between respective lower ends of the first front and rear connecting members; second front and rear connecting members, respective upper ends of which are connected to both ends of the first step board; and a second step board that is connected between respective lower ends of the second front and rear connecting members. In the first front and rear connecting members, one near the wheel is fixed to the vehicle body and the other near the end of the vehicle body is connected in a pivotally movable manner to the vehicle body and is foldable.

The invention claimed is: 
     
       1. A ladder of a working vehicle in a multi-step structure, comprising:
 a first front connecting member and a first rear connecting member that are connected to a lateral side of a vehicle body and between a wheel and an end of the vehicle body and that are juxtaposed with a predetermined space in a vehicle front-back direction; 
 a first step board that is connected in a pivotally movable manner between respective lower ends of the first front connecting member and the first rear connecting member; 
 a second front connecting member and a second rear connecting member, wherein an upper end of one of the second front connecting member and the second rear connecting member is connected in a pivotally movable manner to a first end of the first step board in the vehicle front-back direction, and an upper end of the other of the second front connecting member and the second rear connecting member is connected in a pivotally movable manner to a second end of the first step board in the vehicle front-back direction; and 
 a second step board that is connected in a pivotally movable manner between respective lower ends of the second front connecting member and the second rear connecting member, wherein: 
 an upper end of one of the first front connecting member and the first rear connecting member near the wheel is fixed to the vehicle body, so as to be incapable of any pivotal movement with respect to the vehicle body, 
 an upper end of the other of the first front connecting member and the first rear connecting member near the end of the vehicle body is connected in a pivotally movable manner to the vehicle body and is foldable; the upper end of the other of the first front connecting member and the first rear connecting member near the end of the vehicle body is connected in a pivotally movable manner to a first connecting bracket that is fixed to the vehicle body, and the first connecting bracket comprises a cutout hole that is open downward and that is adapted to receive the other of the first front connecting member and the first rear connecting member. 
 
     
     
       2. The ladder of the working vehicle according to  claim 1 , wherein the second front connecting member and the second rear connecting member are elastically deformable. 
     
     
       3. The ladder of the working vehicle according to  claim 2 , wherein each of the second front connecting member and the second rear connecting member comprises a laminate of a plurality of elastic plates. 
     
     
       4. The ladder of the working vehicle according to  claim 1 , wherein the ladder is folded between a departure-angle-defining line that connects the wheel and a vehicle rear bottom of the vehicle body and connected positions of the first front connecting member and the first rear connecting member to the vehicle body. 
     
     
       5. The ladder of the working vehicle according to  claim 1 , wherein:
 a lower end of the one of the first front connecting member and the first rear connecting member is connected in the pivotally movable manner to a second connecting bracket provided on the first end of the first step board in the vehicle front-back direction, and a lower end of the other of the first front connecting member and the first rear connecting member is connected in the pivotally movable manner to a third connecting bracket provided on the second end of the first step board in the vehicle front-back direction, and 
 each of the second and third connecting brackets provided on the ends of the first step board comprises an upward cutout hole that is open upward, wherein the upward cutout hole of the second connecting bracket is adapted to receive the one of the first front connecting member and the first rear connecting member. 
 
     
     
       6. The ladder of the working vehicle according to  claim 5 , wherein:
 the upper end of the one of the second front connecting member and the second rear connecting member is connected in the pivotally movable manner to the second connecting bracket provided on the first end of the first step board in the vehicle front-back direction, and the upper end of the other of the second front connecting member and the second rear connecting member is connected in the pivotally movable manner to the third connecting bracket provided on the second end of the first step board in the vehicle front-back direction, and 
 each of the second and third connecting brackets provided on the ends of the first step board further comprises a downward cutout hole that is open downward, wherein the downward cutout hole of the second connecting bracket is adapted to receive the one of the second front connecting member and the second rear connecting member and the downward cutout hole of the third connecting bracket is adapted to receive the other of the second front connecting member and the second rear connecting member. 
 
     
     
       7. The ladder of the working vehicle according to  claim 6 , wherein:
 the lower end of the one of the second front connecting member and the second rear connecting member is connected in the pivotally movable manner to a fourth connecting bracket provided on a first end of the second step board in the vehicle front-back direction, and the lower end of the other of the second front connecting member and the second rear connecting member is connected in the pivotally movable manner to a fifth connecting bracket provided on a second end of the second step board in the vehicle front-back direction, and 
 each of the fourth and fifth connecting brackets provided on the ends of the second step board comprises an upward cutout hole that is open upward, wherein the upward cutout hole of the fourth connecting bracket is adapted to receive the one of the second front connecting member and the second rear connecting member and the upward cutout hole of the fifth connecting bracket is adapted to receive the other of the second front connecting member and the second rear connecting member.